OFFSET
1,1
COMMENTS
Choosing the initial value a(1) = 2 seems to produce the most irregular sequence.
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
EXAMPLE
Since a(11) = 28, gpf(28) = 7 and a(7) = 12, then a(12) = 28 + 12 = 40.
MATHEMATICA
Nest[Append[#, (x = #[[-1]]) + If[(p = FactorInteger[x][[-1, 1]]) <= Length@#, #[[p]], 1]] &, {2}, 49] (* Ivan Neretin, Jan 27 2017 *)
PROG
(PARI) gpf(n) = if (n==1, 1, vecmax(factor(n)[, 1]));
lista(nn) = {va = vector(nn); print1(va[1] = 2, ", "); for (n=2, nn, if (gpf(va[n-1]) <= n-1, va[n] = va[n-1] + va[gpf(va[n-1])], va[n] = va[n-1]+1); print1(va[n], ", "); ); } \\ Michel Marcus, Apr 09 2016
CROSSREFS
KEYWORD
nonn,hear
AUTHOR
Cody M. Haderlie, Apr 07 2016
STATUS
approved